Design optimization and standardization of an environmental availability test under both acidic and alkaline conditions

Abstract

The objective of this study was to design a procedure for an environmental availability test under both acidic and alkaline conditions for solid wastes and recycled materials and products. The procedure was designed on the basis of the Dutch availability test NEN 7371. Bottom ash from a municipal solid waste incinerator and copper slag were used as test materials. The infl uences of the type and intensity of liquid stirring apparatus and the open area ratio of the top of the leaching vessel were investigated experimentally, and partial least-squares modeling was applied as multivariate data analysis for the simultaneous evaluation of the three leaching conditions. Interlaboratory validation was then carried out with the participation of seven laboratories in accordance with JIS Z 8402-2/ISO 5725-2. Both repeatability and reproducibility were found to be acceptable, but precise calibration of the pH electrode is required. The proposed procedure will provide suffi cient accuracy as a standard test method. L Side view Solid sample: 16 g, comminuted 0.125 mm. Liquid for leaching: 800 mL in initial volume. Reagents in acid series: HNO 3 ,

The importance of time and other determinants in the assessment of heavy metals release during solid waste management

“…Maximum availability leaching test was conducted according to EA NEN 7371:2004 9 for samples of grain size < 0.125 mm. Availability is defined as the potential upper limit of the element that can be released from a solid material into the aquatic environment 25 . The test is a two-stage test until the eluate pH reaches 7 in the first stage and pH 4 in the second stage, with a liquid to solid ratio of L/S = 50 dm 3 /kg.…”